Invention of safe electric fences has permitted farmers over many years to control the movement of livestock around a farm with "variable geometry fencing" which, being light and requiring no great physical strength, can be moved easily, so considerably improving the efficiency of grasslands farming.
While many fences are powered from the mains, it is often an advantage to have a locally driven fence far from a source of mains power. Batteries, windmills, or solar generators are typically used as an energy source, including battery backup in most cases. There is a need for an effective fence energiser that draws a minimal amount of current from a battery supply, in order to conserve consumption and minimise the size of the generator and battery bank used to power the system.
Furthermore, designers of mains-powered energisers have found difficulty in dissipating heat from within a lightly loaded circuit inside a compact enclosure because if the energiser is in a lightly loaded state more of the pulse energy is dissipated within the box. If the circuit can alter its stored charge in accordance with the immediate requirement, it should dissipate a smaller amount of excess energy within its own components, rather than deliver the energy to the fence.